diff options
| -rw-r--r-- | fs/xfs/scrub/common.c | 22 | ||||
| -rw-r--r-- | fs/xfs/scrub/common.h | 1 | ||||
| -rw-r--r-- | fs/xfs/scrub/parent.c | 16 |
3 files changed, 37 insertions, 2 deletions
diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c index 62b33c99efe4..518bff2be0c9 100644 --- a/fs/xfs/scrub/common.c +++ b/fs/xfs/scrub/common.c @@ -844,3 +844,25 @@ xfs_scrub_metadata_inode_forks( return error; } + +/* + * Try to lock an inode in violation of the usual locking order rules. For + * example, trying to get the IOLOCK while in transaction context, or just + * plain breaking AG-order or inode-order inode locking rules. Either way, + * the only way to avoid an ABBA deadlock is to use trylock and back off if + * we can't. + */ +int +xfs_scrub_ilock_inverted( + struct xfs_inode *ip, + uint lock_mode) +{ + int i; + + for (i = 0; i < 20; i++) { + if (xfs_ilock_nowait(ip, lock_mode)) + return 0; + delay(1); + } + return -EDEADLOCK; +} diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h index 5d78bb9602ab..119d9b6db887 100644 --- a/fs/xfs/scrub/common.h +++ b/fs/xfs/scrub/common.h @@ -156,5 +156,6 @@ static inline bool xfs_scrub_skip_xref(struct xfs_scrub_metadata *sm) } int xfs_scrub_metadata_inode_forks(struct xfs_scrub_context *sc); +int xfs_scrub_ilock_inverted(struct xfs_inode *ip, uint lock_mode); #endif /* __XFS_SCRUB_COMMON_H__ */ diff --git a/fs/xfs/scrub/parent.c b/fs/xfs/scrub/parent.c index fc336807e156..77c6b22c6bfd 100644 --- a/fs/xfs/scrub/parent.c +++ b/fs/xfs/scrub/parent.c @@ -214,7 +214,9 @@ xfs_scrub_parent_validate( */ xfs_iunlock(sc->ip, sc->ilock_flags); sc->ilock_flags = 0; - xfs_ilock(dp, XFS_IOLOCK_SHARED); + error = xfs_scrub_ilock_inverted(dp, XFS_IOLOCK_SHARED); + if (error) + goto out_rele; /* Go looking for our dentry. */ error = xfs_scrub_parent_count_parent_dentries(sc, dp, &nlink); @@ -223,8 +225,10 @@ xfs_scrub_parent_validate( /* Drop the parent lock, relock this inode. */ xfs_iunlock(dp, XFS_IOLOCK_SHARED); + error = xfs_scrub_ilock_inverted(sc->ip, XFS_IOLOCK_EXCL); + if (error) + goto out_rele; sc->ilock_flags = XFS_IOLOCK_EXCL; - xfs_ilock(sc->ip, sc->ilock_flags); /* * If we're an unlinked directory, the parent /won't/ have a link @@ -326,5 +330,13 @@ xfs_scrub_parent( if (try_again && tries == 20) xfs_scrub_set_incomplete(sc); out: + /* + * If we failed to lock the parent inode even after a retry, just mark + * this scrub incomplete and return. + */ + if (sc->try_harder && error == -EDEADLOCK) { + error = 0; + xfs_scrub_set_incomplete(sc); + } return error; } |